diff --git a/src/app/file/file_tests.cpp b/src/app/file/file_tests.cpp
index c87d3fb41..48fd484e8 100644
--- a/src/app/file/file_tests.cpp
+++ b/src/app/file/file_tests.cpp
@@ -46,7 +46,7 @@ TEST(File, SeveralSizes)
       std::sprintf(&fn[0], "test.ase");
 
       {
-        doc::Document* doc = ctx.documents().add(w, h, doc::ColorMode_INDEXED, 256);
+        doc::Document* doc = ctx.documents().add(w, h, doc::ColorMode::INDEXED, 256);
         doc->setFilename(&fn[0]);
 
         // Random pixels
diff --git a/src/app/file/gif_tests.cpp b/src/app/file/gif_tests.cpp
index e7a9a8c12..2ba7085aa 100644
--- a/src/app/file/gif_tests.cpp
+++ b/src/app/file/gif_tests.cpp
@@ -46,7 +46,7 @@ TEST_F(GifFormat, Dimensions)
   const char* fn = "test.gif";
 
   {
-    doc::Document* doc = m_ctx.documents().add(31, 29, doc::ColorMode_INDEXED, 14);
+    doc::Document* doc = m_ctx.documents().add(31, 29, doc::ColorMode::INDEXED, 14);
     Sprite* sprite = doc->sprite();
     doc->setFilename(fn);
     sprite->setTransparentColor(3);
@@ -84,7 +84,7 @@ TEST_F(GifFormat, OpaqueIndexed)
   const char* fn = "test.gif";
 
   {
-    doc::Document* doc = m_ctx.documents().add(2, 2, doc::ColorMode_INDEXED, 4);
+    doc::Document* doc = m_ctx.documents().add(2, 2, doc::ColorMode::INDEXED, 4);
     Sprite* sprite = doc->sprite();
     doc->setFilename(fn);
 
@@ -141,7 +141,7 @@ TEST_F(GifFormat, TransparentIndexed)
   const char* fn = "test.gif";
 
   {
-    doc::Document* doc = m_ctx.documents().add(2, 2, doc::ColorMode_INDEXED, 4);
+    doc::Document* doc = m_ctx.documents().add(2, 2, doc::ColorMode::INDEXED, 4);
     Sprite* sprite = doc->sprite();
     doc->setFilename(fn);
 
@@ -197,7 +197,7 @@ TEST_F(GifFormat, TransparentRgbQuantization)
   const char* fn = "test.gif";
 
   {
-    doc::Document* doc = m_ctx.documents().add(2, 2, doc::ColorMode_RGB, 256);
+    doc::Document* doc = m_ctx.documents().add(2, 2, doc::ColorMode::RGB, 256);
     Sprite* sprite = doc->sprite();
     doc->setFilename(fn);
 
@@ -241,7 +241,7 @@ TEST_F(GifFormat, OpaqueRgbQuantization)
   const char* fn = "test.gif";
 
   {
-    doc::Document* doc = m_ctx.documents().add(2, 2, doc::ColorMode_RGB, 256);
+    doc::Document* doc = m_ctx.documents().add(2, 2, doc::ColorMode::RGB, 256);
     Sprite* sprite = doc->sprite();
     doc->setFilename(fn);
 
@@ -289,7 +289,7 @@ TEST_F(GifFormat, OpaqueRgbQuantizationTwoLayers)
   const char* fn = "test.gif";
 
   {
-    Document* doc(static_cast<Document*>(m_ctx.documents().add(2, 2, doc::ColorMode_RGB, 256)));
+    Document* doc(static_cast<Document*>(m_ctx.documents().add(2, 2, doc::ColorMode::RGB, 256)));
     Sprite* sprite = doc->sprite();
     doc->setFilename(fn);
 
diff --git a/src/doc/color_mode.h b/src/doc/color_mode.h
index 7cbcdf853..fa64f0691 100644
--- a/src/doc/color_mode.h
+++ b/src/doc/color_mode.h
@@ -10,11 +10,11 @@
 
 namespace doc {
 
-  enum ColorMode {
-    ColorMode_RGB,
-    ColorMode_GRAYSCALE,
-    ColorMode_INDEXED,
-    ColorMode_BITMAP
+  enum class ColorMode {
+    RGB,
+    GRAYSCALE,
+    INDEXED,
+    BITMAP
   };
 
 } // namespace doc
diff --git a/src/doc/context_tests.cpp b/src/doc/context_tests.cpp
index 1794617e2..790a8660f 100644
--- a/src/doc/context_tests.cpp
+++ b/src/doc/context_tests.cpp
@@ -15,6 +15,14 @@
 
 using namespace doc;
 
+namespace doc {
+
+  std::ostream& operator<<(std::ostream& os, ColorMode mode) {
+    return os << (int)mode;
+  }
+  
+} // namespace doc
+
 TEST(Context, AddDocument)
 {
   Context ctx;
@@ -23,7 +31,7 @@ TEST(Context, AddDocument)
 
   EXPECT_EQ(32, doc->width());
   EXPECT_EQ(28, doc->height());
-  EXPECT_EQ(ColorMode_RGB, doc->colorMode()); // Default color mode is RGB
+  EXPECT_EQ(ColorMode::RGB, doc->colorMode()); // Default color mode is RGB
 }
 
 TEST(Context, DeleteDocuments)
diff --git a/src/doc/documents.h b/src/doc/documents.h
index d4967280d..248f8cd77 100644
--- a/src/doc/documents.h
+++ b/src/doc/documents.h
@@ -40,7 +40,7 @@ namespace doc {
     bool empty() const { return m_docs.empty(); }
 
     // Add a new documents to the list.
-    Document* add(int width, int height, ColorMode mode = ColorMode_RGB, int ncolors = 256);
+    Document* add(int width, int height, ColorMode mode = ColorMode::RGB, int ncolors = 256);
     Document* add(Document* doc);
 
     // Removes a document from the list without deleting it. You must
diff --git a/src/doc/sprites.h b/src/doc/sprites.h
index 24edbe9db..66e2d43e2 100644
--- a/src/doc/sprites.h
+++ b/src/doc/sprites.h
@@ -39,7 +39,7 @@ namespace doc {
     int size() const { return m_sprites.size(); }
     bool empty() const { return m_sprites.empty(); }
 
-    Sprite* add(int width, int height, ColorMode mode = ColorMode_RGB, int ncolors = 256);
+    Sprite* add(int width, int height, ColorMode mode = ColorMode::RGB, int ncolors = 256);
     Sprite* add(Sprite* spr);
     void remove(Sprite* spr);
     void move(Sprite* spr, int index);